This invention relates to apparatus for delivering medicine to the respiratory system of a patient, and more particularly to an improved hand-held nebulizer system.
Respiratory care devices are known and in widespread use for delivering medicine directly to the respiratory system, thereby maximizing the effectiveness of the medicine. In a typical device of this nature, a stream of gas (which may be ordinary air) is passed through a nebulizer containing the medicine. The medicine is aerosolized and mixed with the gas stream in the nebulizer, and the gas medicine mixture is then inhaled by the patient, causing the mist or fine particles of the medicine to be distributed in the respiratory system of the patient. This is, for example, a common method of administering aerosolized medication to a patient in respiratory distress.
Prior art devices include the "Respirgard II.TM. Nebulizer System" marketed by Marquest Medical Company. In this device a mouthpiece is fastened to the center leg of a wye; one of the other two legs is connected to a nebulizer and the third leg is connected to an exhaust filter. Valves are also provided to cause inspiration through the nebulizer leg and expiration through the filter leg.
The Hudson RCI company markets a device referred to as the "ISO-NEB.TM. system" which is similar in principle to the Respirgard II Nebulizer System except that the ISO-NEB system includes a T coupling instead of a wye.
It is believed that all prior art devices of this general nature include one-way check valves for controlling the direction of gas flow to cause inspiration through the nebulizer and expiration through the filter. The provision of valves is, however, disadvantageous because it adds expense and weight to the unit. Further, valves have a resistance to air flow which could result in excessive inspiratory effort on the part of sick patients.
It is a general object of the present invention to provide an improved apparatus which avoids the above disadvantages and has other important advantages.